What is the difference between a down pillow and a feather pillow?

There are many differences, but the biggest difference is that down traps more air and makes a fluffy, balloon-like, pillow that has "bounce." Feather pillows tend to pack harder and flatten more quickly with use. While either pillow can be made soft, medium or firm, just by adding more or less fill, choose down for its ability to loft, and feather if you prefer a flatter, harder packed pillow.